This invention relates to robotic welding systems and to an improved arc welding torch with integrated optics.
Good arc welds are achieved by adaptively controlling weld parameters and closely centering the weld puddle over the seam to be welded. Optimum weld quality requires continuous sensing of seam to puddle displacement, as close to the puddle as possible, and moving the torch to minimize deviation. Excessive seam to puddle deviation may result in poor weld penetration, weak welded joints, or excessive workpiece warping.
Typically, machine welding is accomplished by programming the torch carrier to generally follow the seam path. This method has no provision for preventing random weld puddle wander from the programmed path. Some welding systems use seam sensors separate from and positioned ahead of the torch. The physical separation of sensor from weld puddle in a separate torch-sensor system prevents precise centering of the puddle over the seam at all points along the path. In addition, separate sensors may limit torch maniulation in restricted areas of the workpiece.
A specific object of the invention is to provide an improved gas tungsten or gas metal arc welding torch with integral optics, a more compact welding torch and seam sensing tool which is capable of simultaneously welding and detecting weld puddle characteristics and seam to puddle deviation. This information can be used to optimize the welding process beyond the capabilities of existing welding systems. The present arc welding torch and system are an improvement over copending application Ser. No. 451,129, filed Dec. 20, 1982, now U.S. Pat. No. 4,491,719, N. R. Corby, Jr., "Light Pattern Projector Especially for Welding", assigned to the same assignee.